This invention relates to a seal for sealing a tube into a housing and, more specifically, to a seal for sealing a fuel pump nozzle into a housing of a fuel sender assembly, wherein the seal has a dual function of providing a fluid-tight seal and of damping vibrations between the fuel pump and the fuel tank.
In the past there have been attempts to provide a seal which will both seal a tube, such as a fuel nozzle, into a housing and also provide damping of any vibrations between the tube and the housing. One such prior seal is shown in FIGS. 1A and 1B. A leading edge 12 of the prior seal is tapered in from the outside edge to the inside edge for receiving the fuel pump spout, and a tail end 14 of the seal is formed with a planar surface. The seal is made out of a resilient elastomeric material in order to seal the tube into the housing and also to dampen vibrations between the housing and the tube.
The prior art seal relies on radial pressure exerted between a fuel pump spout and an inside housing diameter in order to provide an effective sealing function. In order to obtain the necessary radial pressure for maintaining a sealed condition between the fuel pump spout and the housing, the prior art seal must be compressed a significant amount such that assembly of the fuel pump spout, seal and housing has proven to be difficult. In addition, when exposed to fuel or fuel vapors, the seal tends to expand or swell excessively thereby increasing the internal forces within the seal and limiting the ability of the seal to function as a dampening element. Further, the internal forces resulting from the swelling of the seal may be so high as to lead to tearing of the seal when the seal is subjected to vibrations.
Another problem associated with the prior art seal relates to the material requirement for the seal. Specifically, since the prior art seal must be compressed a significant amount in order to establish an effective fluid tight barrier between a fuel pump spout and a housing, the seal must be formed of a highly flexible, and relatively expensive, material which is capable of compressing to conform to the space defined between the fuel pump spout and the inside diameter of the housing.
Accordingly, there is a need for a seal for performing a sealing and dampening function between a fuel pump spout and the inside diameter of a housing which is durable and easy to assemble. Further, there is a need for such a seal wherein the seal may be manufactured of a relatively inexpensive material and wherein the dampening function of the seal is substantially unaffected by swelling of the seal resulting from absorption of fuel and fuel vapors.